Put the following sentences in the negative and interrogative
1) The Managing Director told us about the change of his plans.
2) My boss phoned me yesterday.
3) We were on a business trip last month.
4) They have just discussed the terms of the contract.
5) The secretary has sent the documents by air mail.
6) In June we will produce two new models.
7) They will accept our offer.
8) The hotel was very expensive.
9) They had a meeting the day before yesterday.
10) The plane for Moscow left on time.
I agree with Leigh and Michael - you should try to do this excercise yourself, and post it in Notebook (http://www.italki.com/notebook).
However, I'll show you the first one so you can see the pattern. Just look at how the verb form changes (with an auxiliary verb), plus the word-order for questions:
The Managing Director told us about the change of his plans. (postive)
The Managing Director didn't tell us about the change of his plans. (negative)
Did the Managing Director tell us about the change of his plans? (question)
YOu do need to do theses for yourself and hen I would be happy to correct them Guka :)
Try to do these yourself. Then post them in the notebook for correction.